Electronic display devices such as tablets, eReaders, mobile phones, smart phones, personal digital assistants (PDAs), and other such touch screen electronic display devices are commonly used for displaying consumable content. The content may be, for example, an eBook, an online article or blog, images, documents, a movie or video, and the like. Such display devices are also useful for displaying a user interface that allows a user to interact with the displayed content. The user interface may include, for example, one or more touch screen controls and/or one or more displayed labels that correspond to nearby hardware buttons. The user may interact with the touch-sensitive device using fingers, a stylus, or other implement. The touch screen display may be backlit or not, and may be implemented for instance with an LED screen or an electrophoretic display. Such devices may also include other touch-sensitive surfaces, such as a track pad (e.g., capacitive or resistive touch sensor) or touch-sensitive housing (e.g., acoustic sensor).